Re: [PATCH 06/12] x86/crypto: Fix RBP usage in sha1_avx2_x86_64_asm.S

From	Tim Chen <tim.c.chen@linux.intel.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH 06/12] x86/crypto: Fix RBP usage in sha1_avx2_x86_64_asm.S
Date	2017-09-06 18:20 +0200
Message-ID	<umLdw-4da-15@gated-at.bofh.it> (permalink)
References	<ujT7A-602-9@gated-at.bofh.it> <ujT7A-602-27@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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On 08/29/2017 11:05 AM, Josh Poimboeuf wrote:
> Using RBP as a temporary register breaks frame pointer convention and
> breaks stack traces when unwinding from an interrupt in the crypto code.
> 
> Use R11 instead of RBP.  Since R11 isn't a callee-saved register, it
> doesn't need to be saved and restored on the stack.

These changes seem okay.

Thanks.

Tim

> 
> Reported-by: Eric Biggers <ebiggers@google.com>
> Reported-by: Peter Zijlstra <peterz@infradead.org>
> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
> ---
>  arch/x86/crypto/sha1_avx2_x86_64_asm.S | 4 +---
>  1 file changed, 1 insertion(+), 3 deletions(-)
> 
> diff --git a/arch/x86/crypto/sha1_avx2_x86_64_asm.S b/arch/x86/crypto/sha1_avx2_x86_64_asm.S
> index 1eab79c9ac48..9f712a7dfd79 100644
> --- a/arch/x86/crypto/sha1_avx2_x86_64_asm.S
> +++ b/arch/x86/crypto/sha1_avx2_x86_64_asm.S
> @@ -89,7 +89,7 @@
>  #define	REG_RE	%rdx
>  #define	REG_RTA	%r12
>  #define	REG_RTB	%rbx
> -#define	REG_T1	%ebp
> +#define	REG_T1	%r11d
>  #define	xmm_mov	vmovups
>  #define	avx2_zeroupper	vzeroupper
>  #define	RND_F1	1
> @@ -637,7 +637,6 @@ _loop3:
>  	ENTRY(\name)
>  
>  	push	%rbx
> -	push	%rbp
>  	push	%r12
>  	push	%r13
>  	push	%r14
> @@ -673,7 +672,6 @@ _loop3:
>  	pop	%r14
>  	pop	%r13
>  	pop	%r12
> -	pop	%rbp
>  	pop	%rbx
>  
>  	ret
>

Thread

[PATCH 00/12] x86/crypto: Fix RBP usage in several crypto .S files Josh Poimboeuf <jpoimboe@redhat.com> - 2017-08-29 20:10 +0200
  [PATCH 06/12] x86/crypto: Fix RBP usage in sha1_avx2_x86_64_asm.S Josh Poimboeuf <jpoimboe@redhat.com> - 2017-08-29 20:10 +0200
    Re: [PATCH 06/12] x86/crypto: Fix RBP usage in sha1_avx2_x86_64_asm.S Tim Chen <tim.c.chen@linux.intel.com> - 2017-09-06 18:20 +0200
  [PATCH 12/12] x86/crypto: Fix RBP usage in twofish-avx-x86_64-asm_64.S Josh Poimboeuf <jpoimboe@redhat.com> - 2017-08-29 20:10 +0200
  [PATCH 11/12] x86/crypto: Fix RBP usage in sha512-avx2-asm.S Josh Poimboeuf <jpoimboe@redhat.com> - 2017-08-29 20:10 +0200
  [PATCH 10/12] x86/crypto: Fix RBP usage in sha256-ssse3-asm.S Josh Poimboeuf <jpoimboe@redhat.com> - 2017-08-29 20:10 +0200
  [PATCH 01/12] x86/crypto: Fix RBP usage in blowfish-x86_64-asm_64.S Josh Poimboeuf <jpoimboe@redhat.com> - 2017-08-29 20:10 +0200
  [PATCH 05/12] x86/crypto: Fix RBP usage in des3_ede-asm_64.S Josh Poimboeuf <jpoimboe@redhat.com> - 2017-08-29 20:10 +0200
  [PATCH 07/12] x86/crypto: Fix RBP usage in sha1_ssse3_asm.S Josh Poimboeuf <jpoimboe@redhat.com> - 2017-08-29 20:10 +0200
  [PATCH 02/12] x86/crypto: Fix RBP usage in camellia-x86_64-asm_64.S Josh Poimboeuf <jpoimboe@redhat.com> - 2017-08-29 20:10 +0200
  [PATCH 03/12] x86/crypto: Fix RBP usage in cast5-avx-x86_64-asm_64.S Josh Poimboeuf <jpoimboe@redhat.com> - 2017-08-29 20:20 +0200
  Re: [PATCH 00/12] x86/crypto: Fix RBP usage in several crypto .S  files Eric Biggers <ebiggers3@gmail.com> - 2017-09-02 02:10 +0200
    Re: [PATCH 00/12] x86/crypto: Fix RBP usage in several crypto .S  files Josh Poimboeuf <jpoimboe@redhat.com> - 2017-09-07 02:20 +0200
    Re: [PATCH 00/12] x86/crypto: Fix RBP usage in several crypto .S  files Ingo Molnar <mingo@kernel.org> - 2017-09-07 09:20 +0200
      Re: [PATCH 00/12] x86/crypto: Fix RBP usage in several crypto .S  files Eric Biggers <ebiggers3@gmail.com> - 2017-09-07 20:00 +0200
        Re: [PATCH 00/12] x86/crypto: Fix RBP usage in several crypto .S  files Ingo Molnar <mingo@kernel.org> - 2017-09-07 23:30 +0200
          Re: [PATCH 00/12] x86/crypto: Fix RBP usage in several crypto .S  files Eric Biggers <ebiggers3@gmail.com> - 2017-09-08 20:00 +0200

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